Practical calibration method for instantaneous polarization radar systems utilizing a metal sphere

A practical calibration method is proposed for instantaneous polarization radar systems. The method only needs one measurement by using a metal sphere. The distortions of system and the actual polarization scattering matrix (PSM) of target can be obtained. First, an instantaneous polarization radar system is presented. The system can obtain PSM by a single pulse echo. The dual-polarization antenna can transmit and receive two orthogonal polarization waves. The multilayer micro-strip patch antenna is adopted for this kind of radar system. Second, based on the multi-port network theory, the operation and system errors of instantaneous polarization radar system are analyzed. By making assumption on the cross-talk factors of antenna, distortion matrices of R and T are derived. Finally, the calibration method based on instantaneous polarization measurement is introduced. Simulation results show the performance of this calibration method. The values of calibrated PSM are in agreement with the actual ones after calibration.